CN113177625A

CN113177625A - Method for detecting tearing of RFID (radio frequency identification) label and RFID chip

Info

Publication number: CN113177625A
Application number: CN202110156128.7A
Authority: CN
Inventors: 邸鹏; 李忠
Original assignee: Shanghai Zhaozi Iot Technology Co ltd
Current assignee: Suzhou Zhaozi IoT Technology Co.,Ltd.
Priority date: 2021-02-04
Filing date: 2021-02-04
Publication date: 2021-07-27
Anticipated expiration: 2041-02-04
Also published as: CN113177625B

Abstract

The invention relates to a method for detecting the tearing of an RFID label and an RFID chip, wherein the method comprises the following steps: connecting at least two charging and discharging devices with the RFID chip; initializing the charging or discharging time of each charging and discharging device: charging or discharging each charging and discharging device, recording the charging or discharging time of each charging and discharging device and sending the charging or discharging time of each charging and discharging device to a server for storage; detecting the charging or discharging time of each charging and discharging device in the working process of the RFID chip; encrypting the charging or discharging time of each charging and discharging device and transmitting the encrypted charging or discharging time to a server; and if the detected charging or discharging time of each charging and discharging device changes in proportion to the charging or discharging time of each charging and discharging device stored by the server, judging that the RFID label is not torn, otherwise, judging that the RFID label is torn. The method and the device improve the accuracy of the tearing detection of the RFID label, thereby improving the safety of the RFID label.

Description

Method for detecting tearing of RFID (radio frequency identification) label and RFID chip

Technical Field

The invention relates to the technical field of radio frequency identification, in particular to a method for detecting tearing of an RFID (radio frequency identification) label and an RFID chip.

Background

The RFID technology, i.e. the radio frequency identification technology, is a non-contact automatic identification technology, and its basic principle is to utilize the transmission characteristics of radio frequency signals and spatial coupling (inductive or electromagnetic coupling) or radar reflection to realize the automatic identification of the identified object.

The internet of things refers to a network formed by combining radio frequency identification technology and equipment with the internet according to an agreed communication protocol to intelligently identify and manage information of articles and realize interconnection of the information of the articles. However, with the development of technology and application, the concept of the internet of things is deepened and the extension of the internet of things is expanded. At present, the modern Internet of things can realize organic unification of perception, identification, control, networking interconnection and intelligent processing of objects.

Because the RFID chip can only realize the ID recognition function, the RFID chip is too simple and has a certain distance from the modern Internet of things chip, and the RFID chip is called the Internet of things chip and is slightly reluctant. However, if the sensor, the driving circuit, the interface circuit and the operation unit are integrated into the RFID chip as required, the RFID chip has functions of sensing, controlling, intelligently processing and other attributes of the internet of things in addition to the ID identification function, and the chip also becomes a modern chip of the internet of things.

There is an industry challenge in the field of RFID applications in identifying whether an RFID tag has been torn (i.e., broken). There are several methods currently in use: firstly, the RFID label is subjected to tamper-proof or fragile treatment, and when the RFID label is torn, an antenna of the RFID label can be easily damaged, and finally the label is failed; the RFID chip has an independent loop disconnection detection function and corresponding pins, specific loop disconnection is easily caused when the RFID label is torn, and specific data is written in the RFID chip for marking after the RFID chip detects the disconnection information and is identified by a reader-writer in a specific mode; thirdly, the RFID chip stores the characteristic value (capacitance/resistance/inductance) or the ratio of the characteristic value and the resistance/inductance on the antenna, then the current characteristic value or the ratio of the characteristic value is compared with the original value to judge whether the current characteristic value or the ratio is consistent with the original value or not when the current characteristic value or the ratio is electrified, and if the current characteristic value or the ratio is inconsistent with the original value, specific data is written into the chip to be marked and is identified by a reader-writer in a specific mode. The above solutions partially solve the problem, but have certain disadvantages. The first method has the disadvantages that when the damaged antenna of the RFID tag is repaired (such as the simplest connection back), the RFID tag can recover the function; the second method has the disadvantages that when the specific loop is reconnected after the disconnection (the RFID chip is not powered on before the connection), the RFID chip can not find the disconnection condition; the third method has the disadvantages that the high-precision characteristic value acquisition circuit is complex, so that the cost is high, the stability is poor, and certain potential safety hazards exist in the process of storing the characteristic values in the RFID chip and continuously comparing the characteristic values.

Disclosure of Invention

The invention aims to provide a method for detecting the tearing of an RFID (radio frequency identification) label and an RFID chip, which improve the safety of the RFID label.

In order to achieve the purpose, the invention provides the following scheme:

a method of detecting a tear in an RFID tag, the method comprising:

connecting at least two charging and discharging devices with the RFID chip;

initializing a charging or discharging time of each of the charge-discharge devices: charging or discharging each charging or discharging device, recording the charging or discharging time of each charging or discharging device, and sending the charging or discharging time of each charging or discharging device to a server for storage;

detecting the charging or discharging time of each charging or discharging device in the working process of the RFID chip;

encrypting the charging or discharging time of each charging and discharging device and transmitting the encrypted charging or discharging time to a server;

if the detected charging or discharging time of each charging or discharging device changes in proportion to the charging or discharging time of each charging or discharging device stored by the server, the RFID tag is judged not to be torn, and if not, the RFID tag is judged to be torn.

Optionally, the charge and discharge device is a capacitor.

Optionally, the capacitance comprises a first capacitance and a second capacitance.

Optionally, the first capacitor and the second capacitor are different in capacity.

The invention also discloses an RFID chip, the detection method for the tearing of the RFID label is applied to the RFID chip, and the RFID chip comprises the following steps: the device comprises a tearing detection sensor, a random number generator, an encryption circuit, a data transmission module and at least two interfaces for connecting a charging and discharging device;

the tearing detection sensor comprises a charging or discharging timing circuit, the charging or discharging timing circuit is used for detecting charging or discharging time of each charging or discharging device, the encryption circuit is used for encrypting the charging or discharging time of each charging or discharging device and random numbers generated by the random number generator, and the data transmission module is used for receiving control instructions sent by the server and transmitting the encrypted charging or discharging time of each charging or discharging device to the server.

Optionally, the charge and discharge device is a capacitor.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the RFID chip is connected with at least two charge and discharge devices, the charge or discharge time of each charge and discharge device is initialized, the charge or discharge time of each charge and discharge device is recorded, and the charge or discharge time of each charge and discharge device is sent to a server for storage; detecting the charging or discharging time of each charging or discharging device in the working process of the RFID chip; encrypting the charging or discharging time of each charging and discharging device and transmitting the encrypted charging or discharging time to a server; and judging whether the RFID label is torn or not by detecting whether the charging or discharging time of each charging or discharging device changes in equal proportion to the charging or discharging time of each charging or discharging device stored by the server or not. The method is simple and easy to implement, has low cost, and improves the accuracy of the tearing detection of the RFID label, thereby improving the safety of the RFID label.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a schematic flow chart of a method for detecting tearing of an RFID tag according to the present invention;

FIG. 2 is a schematic diagram of an RFID chip according to the present invention;

fig. 3 is a schematic diagram of an RFID tag including an RFID chip according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Fig. 1 is a schematic flow chart of a method for detecting RFID tag tearing according to the present invention, and as shown in fig. 1, the method for detecting RFID tag tearing includes the following steps:

step 101: and connecting at least two charging and discharging devices with the RFID chip.

Step 102: initializing a charging or discharging time of each of the charge-discharge devices: and charging or discharging each charging or discharging device, recording the charging or discharging time of each charging or discharging device, and sending the charging or discharging time of each charging or discharging device to a server for storage.

Step 103: and detecting the charging or discharging time of each charging or discharging device in the working process of the RFID chip. The method specifically comprises the following steps: and in the working process of the RFID chip, the charging or discharging time of each charging or discharging device is read in sequence.

Step 104: and encrypting the charging or discharging time of each charging and discharging device and transmitting the encrypted charging or discharging time to a server.

Step 105: whether the detected charging or discharging time of each charging or discharging device is changed in equal proportion to the charging or discharging time of each charging or discharging device stored by the server or not is detected.

If the determination in step 105 is no, step 106 is executed.

Step 106: and judging that the RFID label is torn.

If the answer in step 105 is yes, step 107 is executed.

Step 107: and judging that the RFID label is not torn.

The charge and discharge device is a capacitor. The capacitance includes a first capacitance and a second capacitance. The first capacitor and the second capacitor have different capacities.

The following describes a method for detecting a torn RFID tag according to the present invention in detail.

A tear detection sensor is integrated within the RFID chip. The core component of the tearing detection sensor is a charging/discharging timing circuit which respectively charges/discharges external capacitors by a time-sharing multiplexing method and records charging/discharging time, wherein the charging/discharging time can be linearly changed along with the change of the capacitance value. The RFID chip is also internally provided with special instructions which can control the work of the tearing detection sensor and can transmit the charging/discharging time data to the read-write equipment.

Two or more capacitors are arranged on the RFID antenna.

And packaging the RFID chip integrated with the tearing detection sensor on an RFID antenna provided with two or more capacitors to obtain the RFID tag capable of detecting tearing.

An initialization process: and communicating with the RFID tag by using read-write equipment, sequentially reading the charge/discharge time data of each capacitor, and storing the charge/discharge time data of each capacitor in a database of a server. The charging/discharging time data of each capacitor is stored in the server instead of the RFID chip, so that the cost is reduced, and the data security is enhanced.

And (3) detection process: and communicating with the RFID tag by using read-write equipment, sequentially reading the charge/discharge time data of each capacitor, transmitting the charge/discharge time data of each capacitor to an online server, calculating the charge/discharge time data of each capacitor with the initialization data stored in a server database before according to a set algorithm, and judging whether the tag is torn or not according to the calculation result. The setting algorithm changes along with the difference of external capacitance quantity, capacitance value range, label material and the like, and the basic principle of the setting algorithm is as follows: when the RFID label is not torn, although each capacitance value can change along with the change of external conditions such as temperature, humidity and the like, the charge/discharge time of each capacitor can change in the same proportion; when the RFID tag is torn or otherwise changed in state (for example, the external capacitors are connected back after being torn or re-packaged, and the external capacitors are difficult to recover to be completely consistent with the original external capacitors), the measured charging/discharging time of the external capacitors may be changed in an unequal proportion.

The RFID chip is internally provided with a random number generator and an encryption circuit, in the detection process, the charging/discharging time data of each capacitor transmitted to the server comprises a random number and the transmitted data must be encrypted, so that the transmitted data are ensured not to be repeated and illegally known.

The following describes a method for detecting tearing of an RFID tag according to an embodiment of the present invention.

This embodiment is an HF (high frequency) RFID chip with a tear detection sensor integrated into the chip. The core component of the tearing detection sensor is a charging timing circuit, the charging timing circuit can be connected with two capacitors, namely a first capacitor and a second capacitor, the first capacitor and the second capacitor are respectively charged by a time-sharing multiplexing method, and first charging time and second charging time are recorded, wherein the first charging time is the charging time of the first capacitor, the second charging time is the charging time of the second capacitor, and the first charging time and the second charging time can linearly change along with the change of the capacitance value. Of course, the RFID chip is also provided with special instructions, and these special instructions control the operation of the tear detection sensor and transmit the first charging time and the second charging time to the server through the read-write device. The RFID chip is internally provided with a random number generator and an encryption circuit, the transmission of the random number is further included during the first charging time and the second charging time, and the transmission is carried out after the first charging time, the second charging time and the random number are encrypted, so that the communication data are not repeated and are not illegally acquired.

Both the first and second capacitors were obtained on RIFD antennas using existing technology, typically two layers of aluminum foil (area 1 cm square maximum, 0.1 cm square minimum) with a substrate (paper or PET material, approximately 30 microns thick). The absolute values of the two capacitors are very small as can be seen from the capacitance calculation formula, but the ratio of the two capacitors is easily controlled by changing the proportional relation of the areas. Because these two capacitors are very small, it is difficult to accurately measure their capacitance values with ordinary instruments, and their capacitance values can be significantly changed when subjected to tearing or other state changes.

After the RFID chip and the RFID antenna are packaged into the RFID tag, initialization is firstly carried out, wherein in the initialization process, read-write equipment is used for communicating with the RFID tag, the charging time (first charging time and second charging time) data of each capacitor are sequentially read out, and the charging time data are stored in a database of an online server.

The detection process comprises the following steps: and communicating with the RFID label by using read-write equipment, and sequentially reading the first detection charging time of the first capacitor and the second detection charging time of the second capacitor. Since the communication data is mixed with a random number and encrypted, the data flow of each communication is different even if the detected charging time data (the first detected charging time and the second detected charging time) of each capacitor is not changed. Thus, an illegal user cannot obtain the true value of the detected charging time data, and cannot attack the charging time data in a replay attack mode. After the detected charging time data is sent to the online server, the server can decrypt the detected charging time data to obtain the first detected charging time and the second detected charging time. Since the conditions such as ambient temperature and humidity affect the capacitance value, it cannot be guaranteed that the charging time data obtained every time is kept unchanged. However, the first capacitor and the second capacitor will change proportionally with the change of the environmental condition, that is, the detected charging time data of the two capacitors will also change proportionally. The tag is considered to be intact as long as the ratio of the detected charge time data of the two capacitors corresponds to the ratio of the initialized charge time data recorded in the database. Otherwise, the label is considered to be torn or other state change occurs.

The embodiments provided above employ HF (high frequency) communication protocols, and similarly, may be implemented using UHF (ultra high frequency) or LF (low frequency) communication protocols; the embodiment provided above uses two external capacitors, and similarly, can be implemented using three or more external capacitors; the above-provided embodiment adopts the charging time, and similarly, can be realized by adopting the discharging time, and details thereof are not described herein again.

As shown in fig. 2, the present invention also discloses an RFID chip, wherein the method for detecting the tearing of the RFID tag is applied to the RFID chip, and the RFID chip includes: the device comprises a tearing detection sensor 202, a random number generator 203, an encryption circuit 204, a data transmission module 205 and at least two interfaces 201 for connecting a charging and discharging device;

the tear detection sensor 202 includes a charging or discharging timing circuit, the charging or discharging timing circuit is configured to detect charging or discharging time of each charging or discharging device, the encryption circuit 204 is configured to encrypt the charging or discharging time of each charging or discharging device and a random number generated by the random number generator 203, and the data transmission module 205 is configured to receive a control instruction sent by a server and transmit the encrypted charging or discharging time of each charging or discharging device to the server. The encryption circuit 204 ensures that the data transmitted by the data transmission module 205 to the server is not duplicated and is not known illegally.

Fig. 3 is a schematic structural diagram of an RFID tag including an RFID chip according to the present invention, and as shown in fig. 3, the charging/discharging device is a capacitor. Two capacitors are disposed on the RFID antenna 206, including a first capacitor C1 and a second capacitor C2. The first capacitor C1 and the second capacitor C2 have different capacities.

The invention provides a simple, feasible and low-cost method, an RFID chip and an RFID antenna are designed according to the requirements of the detection method for the tearing of the RFID label so as to obtain the RFID label, and the steps provided by the detection method for the tearing of the RFID label are used for detecting whether the RFID label is torn or not without a blind area. By the method for detecting the tearing of the RFID tag, the fact that the RFID tag is repaired after being torn can be discovered, and the fact that the RFID chip is packaged on a new RFID antenna after being taken down can also be discovered.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims

1. A method of detecting a tear in an RFID tag, the method comprising:

connecting at least two charging and discharging devices with the RFID chip;

2. The method for detecting tearing of an RFID tag according to claim 1, wherein the charging and discharging device is a capacitor.

3. The method of detecting tearing of an RFID tag of claim 3, wherein the capacitance comprises a first capacitance and a second capacitance.

4. The method of detecting tearing of an RFID tag of claim 4, wherein the first and second capacitors are of different capacities.

5. An RFID chip, wherein the method for detecting tearing of an RFID tag according to any one of claims 1 to 5 is applied to the RFID chip, and the RFID chip comprises: the device comprises a tearing detection sensor, a random number generator, an encryption circuit, a data transmission module and at least two interfaces for connecting a charging and discharging device;

6. The RFID chip of claim 5, wherein the charge and discharge device is a capacitor.

7. The RFID chip of claim 6, wherein the capacitance comprises a first capacitance and a second capacitance.

8. The RFID chip of claim 7, wherein the first capacitor and the second capacitor are different capacities.